The COVID-19 vaccine developed by Oxford University and AstraZeneca is not likely to be authorized for emergency use in the United States until April 2021, Operation Warp Speed’s chief scientific adviser Moncef Slaoui said Wednesday.
“We project, if everything goes well, that the readout and emergency use authorization may be granted somewhere early in the month of April,” Slaoui told reporters during a briefing with senior officials on the nation’s COVID-19 vaccine program.
Slaoui previously signaled that he expected an emergency authorization for the British drugmaker’s COVID-19 vaccine could come in February. The United States has so far purchased 300 million doses of the Oxford jab against the CCP (Chinese Communist Party) virus.
Currently, vaccines developed by Pfizer and German firm BioNTech, and Moderna and National Institute of Allergy and Infectious Diseases, are being rolled out across the country following Food and Drug Administration (FDA) approval.
Trump administration officials had said they projected 20 million people would get vaccinated against COVID-19, the disease caused by the CCP virus, by the end of the year. According to the Centers for Disease Control and Prevention, more than 12.4 million doses have been distributed as of Dec. 30, but just 2.7 million have been administered.
Slaoui told reporters that recruitment for AstraZeneca’s phase 3 U.S. trial is almost complete, with over 29,000 participants enrolled.
Britain approved AstraZeneca’s vaccine on Wednesday, the first country in the world to do so, saying it had accepted the recommendation from the Medicines and Healthcare Products Regulatory Agency to authorize the jab.
Experts at the agency concluded that the vaccine had met its strict standards of safety, quality, and effectiveness, Britain’s Department of Health and Social Care said in a statement.
AstraZeneca’s COVID-19 vaccine is based on an adenoviral vector that requires only refrigeration and is therefore easier to store, meaning many low- and middle-income countries are relying on it.
In contrast, Pfizer and Moderna’s vaccines, which were created using messenger RNA, need to be stored and distributed at cold temperatures to prevent them from degrading. They rely on segments of genetic material delivered into cells to help stimulate an immune response.
Several scientists have raised doubts about the robustness of results from AstraZeneca’s British and Brazilian trials, showing the shot was 90 percent effective in a sub-group of trial participants. That group, by error initially, received a half dose followed by a full dose. But the efficacy was 62 percent if the full dose was given twice, which was the case for most participants.
Slaoui said it would ultimately be up to the FDA to decide how to evaluate the vaccine for approval in the United States.
He added that he hopes the Johnson & Johnson vaccine candidate, which also uses an adenoviral vector, will receive approval for emergency use in the United States by mid February, describing it as “quite a game changer.”
“We’re hopeful that this vaccine, which is a one shot vaccine, would have equivalent efficacy to those of Moderna and Pfizer,” he said.
Reuters contributed to this report.